Nor, I was just browsing through old posts and found this. I'm glad the Chefs stone is still working for you.

When a manufacturer states that a product will only go to some limit, and a user regularly exceeds that limit, then it's usually only a matter of time before said product fails. In this case, while the price is (still) attractive, I'm guessing the more expensive 16.5" stones out there are more expensive for a reason. For this reason, I'd prefer to go for a stone with a higher operating temperature. As they say, YMMV.